how to get the rpm and timing right without accelerating the engine too much?? on 1990 Mazda B2200

put a ground wire from the green test connector.Set the rpm to 750 on idle and timing on 6. As soon I disconnect the ground wire,the engine accelerate and rpm goes over 800.The repair manual ask me to ground the test connector so i did.Just want to have my rpms right to smog check. Thanks.

1 answer 2 comments
Are you setting the idle speed with the ground connected or just the 'base' timing?
Im setting idle speed and making sure timing is correct.Thats what the underhood label says: idle speed 750rpm and timing on 6 degrees. Just dont understand what is that ground wire connector for ? why do i need to ground it ??
That is for setting the 'base' ignition timing only. Disconnect , then adjust idle. What else was done , leading to the need to make adjustments?